Qualitative Analysis Related to Palynological Characterization and Biological Evaluation of Propolis from Prespa National Park (Greece)

Abstract

Propolis samples from a geographical part of northwest Greece (Prespa National Park, PNP), which is characterized as a plant endemism center and biodiversity hotspot, were characterized through pollen analysis, chemically analyzed, and biologically evaluated. The majority of the studied propolis showed typical chemical constituents (phenolic acids, flavonoids, and chalcones) of European type, while a sample of Mediterranean-type propolis (rich in diterpenes) was also identified. The palynological characterization was implemented to determine the botanical origin and to explain the chemical composition. The total phenolic content and the DPPH assay showed that the European-type propolis samples possessed strong antioxidant activity (86–91% inhibition at 200 μg/mL). Moreover, promising antibacterial activity of the extracts (MIC values 0.56–1.95 mg/mL) and moderate antifungal activity (MIC values 1.13–2.40 mg/mL) were noticed, while the sample with the highest activity had a significant content in terpenes (Mediterranean type). Propolis samples from the PNP area represent a rich source of antibacterial and antioxidant compounds and confirm the fact that propolis is a significant natural product with potential use for improving human health and stimulating the body’s defense. Finally, it is noteworthy that a significant chemical diversity was demonstrated, even in samples from a limited geographical area as this of PNP.

Assessment of Antioxidant and Antimicrobial Properties of Selected Greek Propolis Samples (North East Aegean Region Islands)

“…In our continuous and systematic studies on propolis from different countries all over the world [ 1 , 3 , 18 , 19 , 20 ], we use as internal standards the isolated metabolites from the different studied propolis samples. In this research, further analysis was performed on the sample POi, one of the most diterpene-rich samples from an extremely rarely studied area.…”

“…It deserves to be mentioned that an unexpected increased percentage of glycerol, a substance naturally identified in small percentages, was detected in the majority of the studied propolis, which can be explained by the beekeeping technique with extensive use of oxalic acid strips (impregnated with glycerin) for the fight against Varroa mites. It is noted that neither honey nor wax are affected by this technique [ 26 ], but it is important in the case of propolis because of the impact on the propolis composition quality [ 20 ]. As those high percentages of glycerin do not come from nature, the percentages have been eliminated from the analytical results.…”

“…All extracts were investigated for their antimicrobial activity against the two Gram-positive bacteria Staphylococcus aureus (ATCC 25923) and S. epidermidis (ATCC 12228), the two Gram-positive oral bacteria S. mutans and S. viridians , the four Gram-negative bacteria Escherichia coli (ATCC 25922), Enterobacter cloacae (ATCC 13047), Klebsiella pneumoniae (ATCC 13883) and Pseudomonas aeruginosa (ATCC 227853) and the three pathogen fungi Candida albicans (ATCC 10231), C. tropicalis (ATCC 13801) and C. glabrata (ATCC 28838). All studied samples dissolved in dimethyl sulfoxide (DMSO) were screened for in vitro antibacterial and antifungal activities in Mueller–Hinton or Sabouraud broths, as previously described [ 20 ].…”

Pharmacognostic And Biological Evaluation Of The Extract Of Artemisia Apiacea

“…The absorbance was estimated at a particular frequency, and the rate of cell reasonability was determined in comparison with untreated control cells. These extra subtleties give a thorough comprehension of the strategies utilised for the assortment, validation, extraction, pharmacognostic examination, and natural assessment of Artemisia apiacea extricate in the exploration study (Pyrgioti et al, 2022).…”

Microclimate and Genotype Impact on Nutritional and Antinutritional Quality of Locally Adapted Landraces of Common Bean (Phaseolus vulgaris L.)

“…Archeological records indicate that the Prespa basin has been inhabited for more than six thousand years, while currently, on the Greek side of the region, the lakes are encircled by extensive farmland for the cultivation of beans. The Prespa National Park area (PNP), in 1975, was designated a “Landscape of Outstanding Natural Beauty”, and in 2009, several areas of the PNP were designated “Protected Natural Formation or Landscape Elements” [ 28 ].…”